setting parameters with zigzag~

I’ve been trying to use zigzag~ as a kind of envelope generator (and
yes, I have good reasons for not using adsr~). However, if I send it
a set of values, it triggers every time I change them. My preference
would be to change them when I’m in the mood, but trigger the zigzag
at my leisure. Out of habit, I tried prepending "set" to the list,
only to discover that zigzag doesn’t understand set. this seems
rather unmaxlike of it. So, I have two questions:

1. Is there any particular reason it doesn’t understand set, and
could I encourage one of the C74 geniuses to add a line of code for
the next release?

2. Given the absence of it, is there any other way I could get a list
in without triggering output?